Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(log log interpolation). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University of Texas – Austin

1. Karimi, Parvaneh. Seismic interpretation using predictive painting.

Degree: PhD, Geological sciences, 2015, University of Texas – Austin

Seismic interpretation plays a crucial role in extracting geologic information from seismic images in order to provide a better understanding of the earth's subsurface. Although there are different methods introduced in structural interpretation and stratigraphic interpretation to evaluate and predict reservoir properties, the challenge of predicting lithological and petrophysical properties of reservoir, revealing features that appear more subtle in conventional seismic data, and automating common interpretation tasks still remain hot topics among geophysicists. Developments in interpretation algorithms and attributes help interpreters to achieve a better understanding of features and properties of interest, leading to a better interpretation of seismic data which can dramatically reduce the possibility of dry wells in oil and gas exploration. Therefore, there is a room for improving the accuracy of current methods and algorithms and prompting novel ideas in the field of interpretation and attributes. This dissertation consists of six main parts. In the first part, I review the predictive painting method, which plays a fundamental role in the proposed methods. I employ predictive painting to generate horizon cubes and to spread information in 3D seismic volumes by following the local structure of seismic events. Next, I review nonlinear structure-enhancing filtering which is applied along seismic events in order to improve lateral continuity and remove random noise. Next, I introduce a new coordinate system and framework for seismic interpretation and processing. The stratigraphic coordinates are aligned with horizons, and the vertical direction in stratigraphic coordinates corresponds to the direction normal to the major reflection boundaries. In the presence of dipping layers any data processing and interpretation tasks in which the vertical direction is commonly assumed to be normal to reflection boundaries may yield biased and inaccurate results. In contrast, the stratigraphic coordinate system offers a local reference frame naturally oriented to sample the unbiased seismic waveform and, hence, promises to yield more accurate results. Next, I develop a novel attribute for highlighting faults and other discontinuities. The conventional coherence measures operate on a spatial window of neighboring traces and a temporal analysis window of samples above and below the analysis point and can hardly cope with non-stationarity in fault information. In contrast, the proposed method involves neither temporal nor spatial windows in coherence computation which honors non-stationary changes of fault information and achieves high resolution in both vertical and lateral directions. After that, I introduce a novel approach to computing volumetric curvature. The key idea is to transfer seismic image into a coordinate frame in which geometry follows the natural shape of each reflector, therefore assigning a horizon to each point in the seismic data volume. The proposed approach also enables multispectral curvature… Advisors/Committee Members: Fomel, Sergey B. (advisor), Moscardelli, Lorena (committee member), Spikes, Kyle (committee member), Wilson, Clark (committee member), Wood, Lesli (committee member).

Subjects/Keywords: Seismic interpretation; Seismic attribute; Spectral decomposition; Acoustic impedance inversion; Volumetric curvature; Well-log interpolation

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Karimi, P. (2015). Seismic interpretation using predictive painting. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32625

Chicago Manual of Style (16th Edition):

Karimi, Parvaneh. “Seismic interpretation using predictive painting.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed October 31, 2020. http://hdl.handle.net/2152/32625.

MLA Handbook (7th Edition):

Karimi, Parvaneh. “Seismic interpretation using predictive painting.” 2015. Web. 31 Oct 2020.

Vancouver:

Karimi P. Seismic interpretation using predictive painting. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2020 Oct 31]. Available from: http://hdl.handle.net/2152/32625.

Council of Science Editors:

Karimi P. Seismic interpretation using predictive painting. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32625


Brigham Young University

2. Hakala, Tim. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.

Degree: PhD, 2006, Brigham Young University

A new method of adaptive impulse control is developed to precisely and quickly control the position of machine components subject to friction. Friction dominates the forces affecting fine positioning dynamics. Friction can depend on payload, velocity, step size, path, initial position, temperature, and other variables. Control problems such as steady-state error and limit cycles often arise when applying conventional control techniques to the position control problem. Studies in the last few decades have shown that impulsive control can produce repeatable displacements as small as ten nanometers without limit cycles or steady-state error in machines subject to dry sliding friction. These displacements are achieved through the application of short duration, high intensity pulses. The relationship between pulse duration and displacement is seldom a simple function. The most dependable practical methods for control are self-tuning; they learn from online experience by adapting an internal control parameter until precise position control is achieved. To date, the best known adaptive pulse control methods adapt a single control parameter. While effective, the single parameter methods suffer from sub-optimal settling times and poor parameter convergence. To improve performance while maintaining the capacity for ultimate precision, a new control method referred to as Adaptive Impulse Control (AIC) has been developed. To better fit the nonlinear relationship between pulses and displacements, AIC adaptively tunes a set of parameters. Each parameter affects a different range of displacements. Online updates depend on the residual control error following each pulse, an estimate of pulse sensitivity, and a learning gain. After an update is calculated, it is distributed among the parameters that were used to calculate the most recent pulse. As the stored relationship converges to the actual relationship of the machine, pulses become more accurate and fewer pulses are needed to reach each desired destination. When fewer pulses are needed, settling time improves and efficiency increases. AIC is experimentally compared to conventional PID control and other adaptive pulse control methods on a rotary system with a position measurement resolution of 16000 encoder counts per revolution of the load wheel. The friction in the test system is nonlinear and irregular with a position dependent break-away torque that varies by a factor of more than 1.8 to 1. AIC is shown to improve settling times by as much as a factor of two when compared to other adaptive pulse control methods while maintaining precise control tolerances.

Subjects/Keywords: control; position; adaptive; impulsive; settling-time; nonlinear friction; pulses; displacements; precise; tolerances; log-spaced; update; distributed; learning; Coulomb; Stribeck; Tomizuka; Yang; AIC; PID; MRAC; STR; RTAI; Linux; FreeBSD; kernel modules; microcontroller; convergence; practical; self-tuning; methods; techniques; limit-cycles; steady-state; error; zero; stable; stability; bound; envelope; partitioned; scheme; lookup-table; multi-point; adaptation; repeatable; mean; servo; motor; exponential; square-law; rise-time; real-time; log-log interpolation; pro-forma; curve-fit; sensitivity; compliance; variable; static; dynamic response; torque; acceleration; velocity; optical encoder; parameters; evolution; fixed-law; enhanced split; weighting; initialization; trajectory; layered processes; Mechanical Engineering

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hakala, T. (2006). Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. (Doctoral Dissertation). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd

Chicago Manual of Style (16th Edition):

Hakala, Tim. “Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.” 2006. Doctoral Dissertation, Brigham Young University. Accessed October 31, 2020. https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd.

MLA Handbook (7th Edition):

Hakala, Tim. “Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.” 2006. Web. 31 Oct 2020.

Vancouver:

Hakala T. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. [Internet] [Doctoral dissertation]. Brigham Young University; 2006. [cited 2020 Oct 31]. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd.

Council of Science Editors:

Hakala T. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. [Doctoral Dissertation]. Brigham Young University; 2006. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd

.